1, 1&#39;-bis[(biscyanoloweralkyl)carbamoyl] methyl-4, 4&#39;-dihalide and 1, 1&#39;-bis[(bislow-eralkoxyloweralkyl)carbamoyl]methyl-4, 4&#39;-dihalide derivatives of bipyridine



United States Patent This application is a divisional of Ser. No.250,786, filed Jan. 11, 1963, now Patent No. 3,251,839.

The invention relates to new bipyridylium quaternary salts, to processesfor their preparation and to herbicidal compositions containing them.

U.K. specification No. 813,532 discloses the use as herbicides ofcompounds of the formula:

where R and R are alkyl radicals of not more than four carbon atomswhich are substituted with a carbamyl or N-substituted carbamyl group;and X" is an anion.

We have now found, according to the present invention, that certainN-substituted carbamyl compounds of the formula shown above showselective herbicidal activity against broad-leafed species compared withtheir activity against grass species. The selective compounds are thoseof the formula:

where R and R are cyanoalkyl or alkoxyalkyl of 2, 3 or 4 carbon atomsand X is an anion. The anion X- can be a monovalent ion, for examplechloride, iodide, or bromide, or a divalent ion-where of course thesymbol 2X in the above structural formula represents a single ion ratherthan two monovalent ions. The choice of anion depends to a large extentupon the solubility of the respective salts in water and upon the easewith which the salts can be prepared.

The invention also consists in a process for the preparation of thecompounds of the invention, in which 4,4- bipyridyl or a monoquaternarysalt of the formula:

oo-oHzN N X- R2 where R R and X- have the meanings given above, isquaternized with a suitable quaternizing agent. The process can beperformed by simply heating a mixture of 4,4- bipyridyl (or themonoqu-aternary salt as the case may be) with the quaternizing agent.However, in some instances, especially where operating on a large scale,it may be more convenient to use a suit-able liquid as a solvent ordiluent for the reactants.

The invention includes herbicidal compositions containing as activeingredient a compound of the invention, and a carrier for the activeingredient. The composition can, for example, be a liquid compositionobtained by dissolving or dispersing the active ingredient in a suitableliquid diluent, for example water or a suitable organic liquid. Theherbicidal composition alternatively can be in the form of a powder inwhich the active ingredient is in 3,336,325 Patented Aug. 15, 1967 "iceadmixture with a powder diluent. The compositions can contain a wettingor dispersin agent to facilitate their use as spray compositions, orindeed can contain any other type of substance known to the art as beingsuitable as an adjuvant in herbicidal composiitons, for instancestickers, binders, corrosion inhibitors and coloring agents.

Any wetting or dispersing agent used in the herbicidal compositionsshould preferably be a nonionic surf-ace active compound for instance anethylene oxide-octyl phenol condensate, or a cationic compound, so as toavoid any undesirable interaction between the surface active compoundand the bipyridylium salt which might take place if an anionic compoundwere to be used as surfaceactive compound.

The invention further consists in a method of killing, idesiccating orotherwise severely damaging undesirable vegetation, in which thevegetation is treated with an effective amount of a compound orherbicidal composition of this invention.

. The invention is illustrated by the following examples:

Examples 1-4 A number of substituted 4,4-bipyridylium dichloridesaccording to the invention as shown below were made by reacting theappropriate N,N-disubstituted chloroacetamide with 4,4-bipyridyl. Morespecifically, the chloroacetamide and the 4,4-bipyridyl were heated andstirred together at C., until a homogeneous liquid was obtained. Thetemperature of this liquid was then raised to C. at which temperature avigorous reaction took place and the mixture solidified. After heatingthe solidified mixture for 30 minutes, the solid was crushed, washedwith acetone and recrystallized from about 300 ml. of ethanol.

The products thus prepared may be illustrated by the structural formula:

and were obtained using a chloroacetamide of the formula:

In each instance, the chloroacetamide and 4,4-bipyridyl were used in amolar ratio in the range 1:1 to 1.1:1.

The products are identified in the table below by the meaning given tothe group and the melting point shown against the products are thoseobtained using a sample of the product which has been purified byrecrystallization, melting in each instance being accompanied bydecomposition of the sample under test.

These products have been tested for herbicidal activity against bothbroad-leafed plant species and grasses, and the results are expressed inthe right-hand columns of the table. Under the heading HerbicidalActivity is shown the amounts (in lb./acre) of the various compounds,expressed in terms of their respective cations, found necessary toobtain a 50% kill of the species tested 14 days after application to thetest plants. The broadleafed and grass species (referred to in the tableunder the respective headings B and G) were as follows:

Broad-leafed species:

Sugar beet (Beta vulgaris) Mustard (Sinapis alba) Kale (Brassicaoleracea) Clover (T rifolium pratense) TABLE I Products of ExamplesHerbicidal activity Ex. N0. R1 Index of Water of M.P. Selectivity Ncrystallisation (dt(a Cm)p.) B G N(CHz-CH2OC2H5) H2O 244 0. 067 28 420N(CH2CH2OCH3)2 258 0.030 6. 5 215 N(CHz-CN)2 320 0.17 5. 0 30 N(CHz-CH2CN)2 Anhydrous 271 0.33 8 24 Redshank (Polygonum persicaria)Mayweed (Matricaria inodora) 25 Grass species:

Wheat T riticum vulgare) Wild oats (Avena fatua) Barley (H ordeumsativum) Cocksfoot (Dactylis glomerata) species were sprayed withaqueous solutions of the test substances at a range of concentrations,The herbicidal damage caused to each batch was visually assessed 14 daysafter spraying as a percentage, taking undamaged control plants as 0%and completely dead plants as 100%.

The mean values obtained against all the broad-leafed species and thegrass species at each particular concentration was then calculated andthese mean values were plotted against concentration on a logarithmicscale. From The invention is defined in the following claims wherein weclaim:

1. A 4,4'-bipyridylium quaternary salt of the formula:

wherein R and R are selected from the group consisting of cyanoalkyl andalkoxyalkyl of from 2 to 4 carbon atoms and X is an anion.

2. A quaternary salt according to claim 1 wherein R and R aremethoxyethyl groups and X is chloride. 3. A quaternary salt according toclaim 1 wherein R and R are ethoxyethyl groups and X- is chloride.

References Cited FOREIGN PATENTS 7/1963 Belgium.

OTHER REFERENCES Chem. Abstracts, vol. 61, par. 1837-8 (1965).

WALTER A. MODANCE, Primary Examiner.

A. ROTMAN, Assistant Examiner.

1. A 4,4''-BIPYRIDYLIUM QUATERNARY SALT OF THE FORMULA:1,1''-DI(R1-N(-R2)-CO-NH2-)-4,4''-BIPYRIDYLIUM 2 X(-) WHEREIN R1 AND R2ARE SELECTED FROM THE GROUP CONSISTING OF CYANOALKYL AND ALKOXYALKYL OFFROM 2 TO 4 CARBON ATOMS AND X- IS AN ANION.